The invention relates to apparatus and methods for use in testing gas pressure reduction equipment.
Such equipment is usually mounted on so-called skid units or is more compact and in the form of control modules, which commonly are installed in a pit below the surface of the ground. Such equipment is hereinafter called xe2x80x9cpr equipmentxe2x80x9d.
The apparatus is intended to form part-of computer-aided diagnostic test equipment by which diagnostic testing of skid units and gas control modules can be performed. In particular it is intended to form a portable diagnostic system for testing pr equipment in situ. Such testing is required to perform static and dynamic tests on the various regulator valves, and safety devices such as relief valves, slamshut and stream selection valves and so on incorporated in skid units or control modules without the need for any disassembly and to obtain accurate pressure set points. The testing also allows identification of changes in performance owing to gradual wear and tear by comparison of results with those obtained on a previous occasion.
According to the invention there is provided a portable diagnostic system for testing pressure reduction equipment in situ, said system including;
means for connecting at least one displacement transducer to the reduction equipment;
means for detecting a fluid pressure;
control means for selecting an output fluid pressure for
testing the reduction equipment;
means for receiving valve displacement information from at least one transducer in dependence on selected and/or detected pressure to determine the degree of movement of the valve relative thereto.
After the initial data gathering process has been completed it is possible for the operator to interrogate the computer preferably forming part of the system to identify which component may be at fault when the results criteria are not met.
A high standard of maintenance records will be achieved by the simple process of downloading and storing test results on the office computing system.
The computer includes a display and enables a knowledge-based expert system to be employed. The apparatus enables a very complex set of tests to be carried out relatively easily. A program disc used in the computer enables all instructions and prompts to be displayed on the computer display screen.
The apparatus supplies gas to various points on the equipment to be tested and gas flowrate and gas pressure are measured and this information is made available to the computer. Displacement transducers and gas pressure transducers are mounted on the pr equipment and the information derived by the transducers is made available to the computer. The duties of the computer include the calculation of the rates of rise and fall of pressure of the gas fed to the pr equipment as well as the calculation of the rates of rise and fall of pressure of the gas at the various components of the equipment. The computer""s duties also include the calculation of the rates of opening and closing movement of the various components of the pr equipment.
The apparatus controls the supply of gas to the pr equipment by means of an array of valves, including a valve which passes gas at all positions of the valve member beyond the closed position and the computer""s duties include the generation of signals controlling the actuator of that valve, as well as the actuators of the on/off valves.
The apparatus is used as computer-aided diagnostic test equipment to perform any combination of a number of tests which the software used in the computer has been written to perform. The apparatus enables such combinations of tests to be readily performed.
Further, according to the invention apparatus having a gas inlet and a gas port for use in testing gas pressure reduction equipment comprises:
first, second and third valves,
the first and second valve having a respective inlet and outlet,
the third valve having first and second valve ports,
the inlet of the first valve communicating with said gas inlet,
the outlet of the first valve communicating with both the inlet of the second valve and the first valve port of the third valve,
the outlet of the second valve communicating with the atmosphere,
the second valve port of the third valve communicating with said gas port,
the third valve having a valve member and means for moving the valve member to a fully closed position and to a fully open position and to intermediate positions therebetween.
Said third valve is preferably associated with a position transducer which can produce an electrical output indicative of the position of said third valve member.
Said apparatus preferably has a fourth valve having an inlet and an outlet, the inlet of the fourth valve communicating with the gas inlet and the outlet of the fourth valve communicating with said gas port.
Said apparatus preferably has a fifth valve having an inlet and an outlet, the inlet of the fifth valve communicating with said gas port and the outlet of the fifth valve communicating with the atmosphere.
Further, according to the invention a method of testing gas pressure reduction equipment using apparatus according to the invention comprises comparing the results obtained with results obtained on a previous occasion of carrying out the method in order to identify changes in performance of the equipment.
The method may comprise interrogation of said computer to identify which component of the equipment may be at fault when the results show that a predetermined standard is not met.
The method may comprise downloading and storing test results on a computing system in order to generate maintenance records.
The method may comprise controlling by means of software used in said computer the rate of pressure rise and the rate of pressure fall in the gas applied to a component of the equipment.
An embodiment of apparatus for use in testing gas pressure reduction equipment will now be described by way of example with reference to the accompanying drawings, in which: